import java.util.ArrayList;

public class HelloWorld {
    public static void main(String[] args) {
        System.out.println("Hello, World");
        ArrayList<String> friends = new ArrayList<>();
        friends.add("peter");
        friends.add("paul");
        System.out.println(friends);
        friends.set(0, "Lucy");
        friends.add(1, "peter");
        System.out.println(friends);
    }
}